The Sand-Fill Base is designed to hold approx. 50 pounds of sand. The twist lock cover keeps the sand inside the base. Two carrying handles make movement and placement an easy job. The low profile 4 inch high base easily clears vehicle undercarriages and can even support the weight of any vehicle.The drum tops and bases are manufactured to snap-lock around the entire perimeter of the drum with a unique lip, or flange, design of each drum and base for positive locking. Designed to stay together when dragged or moved around construction sites.